Apparatus for cutting a continuously cast metal strand

ABSTRACT

THE INVENTION COMPRISES A SUPPORT THAT MOVES ALONG WITH A CONTINUOUS CAST STRAND AND THAT SUPPORTS TWO FLAME CUTTING TORCHES. THE TORCHES MOVE TRANSVERSELY TO THE CAST STRAND ALONG PATHS PRESCRIBED BY ESTABLISHED GUID RODS, AND AFTER A SLAB IS SEVERED FROM THE CAST STRAND THE APPARATUS RETURNS TO ITS INITIAL POSITION. THE APPARATUS IS ADAPTED TO CROP THE HEAD END FROM STRANDS AS WELL.

United States Patent [72] Inventors KurtReinfeld;

Emmanuel V. Gouye, Pittsburgh, Pa. 812,979

266/23X l64/263X 164/263X 266/23 3,462,134 8/1969 Michelson 3,497,1952/1970 Kalkhof....... 3,511,489 5/1970 Field Primary Examiner Robert D.Baldwin [21 Appl. No,

[22] Filed Apr. 3, 1969 [45] Patented June 28, 1971 [73] AssigneeKoppers Company, Inc.

54 APPARATUS F UT A CONTINUOUSLY Att0rneys-Sherman H. Barber and Olll'lE. Williams CAST METAL STRAND ABSTRACT: The invention comprises asupport that moves along with a continuous cast strand and that supportstwo flame cutting torches. The torches move transversely to the caststrand along paths prescribed by established guide rods, and after aslab is severed from the cast strand-the apparatus returns to itsinitial position. The apparatus is adapted to crop the head end fromstrands as well.

269; 266/23 (K), 23 ii 83/319, 320

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SHEET 6 OF 7 INVENTORS xuer FE/NFELD I EMMANUEL M 601/ YE PATENTED JUN28 IHYI SHEET 7 BF 7 INVENTORS KURT REINFELD l EMMANUEL M GOUYE APPARATUSFOR CUTTING A CONTINUOUSLY CAST METAL STRAND BACKGROUND OF THE INVENTIONIn continuous casting installations wherein the cast strand is curvedtoward the horizontal plane, the cast strand usually passes through astraightening device and then passes a cutting ofi station at which thestrand is severed either with a flying saw or with an oxyacetyleneburning torch.

The cutting mechanism must be moved along a path parallel to the pathtraversed by the cast strand, and the cutting mechanism must move at thesame speed at which the strand is moving. Then, after cutting a slab orbillet of desired length from the continuous cast strand, the cuttingmechanism returns to its original starting position. The billet or slabmoves along a runout table toward a stacking device.

Various types of apparatus are available in the prior art to cut acontinuous cast strand into billets of desired length, where the crosssection of the billet is square and is not overly large. However,completely satisfactory apparatus for cutting a slab from a continuouscast strand is not yet available in the prior art, principally because aslab is so much wider than a billet it requires more than one flamecutting torch to sever a slab from a wide continuous cast strand. Fullysatisfactory mechanism for moving two flame cutting torches across awide continuous strand has not been available heretofore in the priorart.

How the apparatus of the present invention meets the need for a moresatisfactory slab cutting apparatus will be apparent to those skilled inthe art from the following description of one embodiment and amodification of the embodiment of the present invention.

SUMMARY OF THE INVENTION Apparatus for cutting slabs from a continuouscast strand includes fixed frames that support cutting torch guides.Torches mounted to a carriage that is motivated by the moving strand areguided by the torch guides and cut a slab from a strand as the carriagemoves along with the strand. Strand supporting rollers automaticallyretract as the torches approach them, and move back into supportinglocation after the torches pass by.

For a further understanding of the present invention and for advantagesand features thereof, reference may be made to the following descriptiontaken in conjunction with the accompanying drawings which show for thepurpose of exemplification embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings illustrate one embodimentand a modification of the embodiment of the invention wherein:

FIG. I is a schematic perspective view of apparatus in accordance withthe invention;

FIG. 2 is a plan view of the apparatus of FIG. I;

FIG. 3 is a side elevational view of the apparatus of FIG. 1 with someportions shown in section;

FIG. 4 is a sectional view along line IV-IV of FIG. 3;

FIG. 5 is a schematic perspective view of a modification of theapparatus of FIG. 1;

FIG. 6 is a plan view of a portion of the apparatus of FIG. 5; and

FIG. 7 is a side elevational view of the apparatus of FIG. 6.

DETAILED DESCRIPTION Referring to FIG. I, cutting apparatus 11 inaccordance with the invention includes: a yoke 13 that has rollers 15coacting with spaced apart parallel rails 17 to which are mounteddisengaging cams 19; a pair of spaced apart frames 21, 23 which straddlethe parallel rails 17; a pair of beams 25, 27 that are pivotally mountedat the other end to laterally adjustable slab feeler blocks 29, 31supporting slab side feeler rollers 33, 35; and a torch carriage frame37 having rollers 39 that cooperate with the side rails 17.

LII

The yoke 13 comprises a transversely extending box beam type structure41 that supports the side rollers 15, and that also supports a pluralityof horizontally arranged other rollers 43. These rollers 43 abut theleading edge 45 of a continuous cast strand 47. The rollers 43, as shownin FIG. 3, are disposed below the side rails 17. To the ends of thetransversely extending box beam type structure 41, there are fixedelongate rearwardly extending side connecting arms 49, 51 that are pinconnected, as at 53, to elongate spaced apart parallel bars 55, 57. Thebars 55, 57 are spaced outwardly from and parallel to the rails 17, asshown in FIGS. 1 and 4, and are perforated, as at 58, to allow forrelocating the pin 53 as desired.

From FIGS. 3 and 4, it will be noted that the conventional runout tablerollers supporting structure, which supports the rails 17 and includes ahollow elongate bar 59 and an l-beam 61, is discontinuous in way of theapparatus 11. The structure supporting the apparatus 11 includes threeopposed pairs of roll stands 63. Of course, in many installations alarger number or a lesser number of roll stands may be used if desired.

Each roll stand 63 includes a vertical frame 65 which has an outwardlyand upwardly projecting support arm 67 that carries the rails 17 andhollow bar 59, as well as a roller 69 on which the bar 55 rests. Eachframe 65 is bolted to a suitable structure as shown in FIG. 3.

On the opposed inner sides of the frame 65 there is pivotally mounted,as at 71, an elongate tie member 73 to the end portions of which arejournaled cutting table support rolls 75, 77. The elongate tie member 73has an oval hole 79 in which the pivot pin 71 acts, for a purpose thatwill be described hereinafter.

Associated with each roll stand 63 and with the upper roller of the pairof rollers that are mounted to the tie member 73, is a latch 81 thatincludes a horizontal shaft 83, a counterweight 85, and a latch dog 87shaped about as shown in FIG. 3. Stops 89 are fixed to the tie member 73about where shown in FIG. 3, and the upper stop 89, engages the latch 81to maintain the roller 75, for example, in the vertical position; roller77 is then maintained in the lower position.

Referring again to FIGS. 2 and 3, the torch carriage frame 37 supports apair of transversely extending spaced apart rods 91, 93 on which a pairof burning torches of a known type, such as oxyacetylene torches 95, 97,travel. Each torch has a roller carriage 99 that coacts with a pair ofthe rods 91, 93.

The torches 95, 97 also have a pair of other roller carriages 101 and103 (FIG. 4). The roller carriage 101 of torch coacts with a cam rod 105that is mounted to the upper surface of the adjustably positionable beam27, and the roller carriage 103 of torch 95 coacts with a cam rod 107mounted to the lower surface of the adjustably positionable beam 27.Likewise, the roller carriage 101 of torch 97 coacts with a cam rod 109that is mounted to the upper surface of the adjustably positionable beam25, and the roller carriage 103 of torch 97 coacts with a cam rod 1 11that is mounted to the lower surface of the beam 25. The cam rods 105,107, 109, 111 have the general shape as shown in FIG. 2, and aresupported by vertical members 113 that are connected to pivotable plates115 mounted to the beams 25, 27.

The apparatus of the invention is operated in the following manner.

Initially, the yoke 13 is located from the transverse centerline of thetorches 95, 97 a distance that is equal to the length of the slab thatis to be cut from the continuous cast strand 47. The pin 53 is theninserted in an appropriate hole 58 in the bars 55, 57 thereby fixing theyoke 13 in position.

Disengaging cams 19 are then located and pinned to the rails 17 at adistance from the yoke 13 that is slightly greater than the distancetravelled by the yoke during the time it takes the torches to cut theslab.

The cam rods I05, 107 and 109, 111 are then set in position, by pivotingand fixing the plates 115, to give the torches the desired transversespeed and motion; it will be observed that the upper cam rods 105, 109cross over the lower cam rods 107, 111, as shown in FIG. 2, whichprovides for a pivoting motion of the torches in a vertical planetransverse to the cast strand 47 The distance of the torch tip from thetop of the slab is preset by means of an adjusting rack and pinion 117that is furnished with the torch. Then, the torch cooling water and thecarriage cooling water is turned on so that the water circulates throughconduits 119, 121, as suggested in FIG. 4. Thereafter, the torch fuel isignited at the torch tip to maintain a standby flame that is about 6inches long.

After the leading edge 45 of the continuous strand 47 passes the siderollers 33, 35, they are moved laterally toward the strand by turning acrank 123 fixed to a right and left-hand threaded Saginaw screw 125,until the side rollers 33, 35 contact the sides of the strand. Thelateral movement of the side rollers 33, 35 also moves the feeler blocks29, 31, and the pivotally attached ends of the beams 25, 27 toward eachother.

The leading edge 45 of the continuous cast strand 47 advances from leftto right, as viewed in FIG. 2, and abuts the rollers 43, as suggested inFIGS. 2 and 3. Further left to right advancement of the cast strand 47moves the yoke 13 and the torch carriage frame 37 in a left to rightdirection, since the yoke and the torch carriage frame areinterconnected by means of the side arms 49,51 and the bars 55, 57.

The torches 95, 97 are initially positioned where shown in FIG. 4 by thedotted outline. That is, the torches are disposed in a downward andoutward direction away from the cast strand 47. But, as the torchcarriage frame 37 advances from left to right in FIG. 2, the torches 95,97 move toward each other and they pivot about the horizontal supportaxes 124 and 126 respectively (FIG. 4). Since the torches 95, 97 arecooperative with their respective cam rods 105, 107 and 109, 111, thetorches follow the path determined by these cam rods.

As the torches travel longitudinally a first distance A (FIG. 2) theyalso move laterally so that the torch tips are adjacent the lateraledges of the cast strand. During the time the torches move through thedistance A, the preheat fuel valve (not shown) of each torch is fullyopened either manually or automatically.

As the torches travel longitudinally a second distance B (FIG. 2.), thepreheat flames are maintained at the edges of the cast strand forpreheating, and the cutting oxygen valve (not shown) is opened eithermanually or automatically.

During the next interval of travel, C, the torches cut the continuouscast strand almost across its width. But, during the next interval oflongitudinal travel, D, torch 95 is moved outwardly due to the sharpchange in direction of the cam rods 105, 107 (FIG. 2), and automaticallythe cutting flame is reduced to the standby flame mentioned previously.The torch 97, however, continues to cut the strand beyond thecenterline, since there is no abrupt change in the shape of the cam rods109, 111. There is provided, then an additional overtravel length, E, onthe cam rods 105, 107 and 109, 111, extending beyond the distance D, toinsure that the single torch 97 cuts through the middle portion of thecast strand and completely severs a slab from the cast strand.

When the torches travel through the distance E, which is the overtraveldistance mentioned previously, the cutting flame of torch 97 isautomatically reduced to a standby flame. At the same time, the yoke isdisengaged from the slab when the rollers 15 ride up the arcuate surfaceof the cams 19 to the position shown in phantom outline FIG. 3. In sucha situation, the rollers 45 are raised high enough so that the slab canpass beneath them.

Just as soon as the torches have completely cut the cast strand andafter the yoke has become disengaged from the slab, the slab is movedrapidly toward the right and away from the east end to prevent anypossibility of the hot strand being rewelded to the slab.

The yoke, arms, and torch carriage frame then return to the initialposition under the influence of a set of counterweights 127, 129 actingon the carriage frame through wire cables 131, 133 and sheaves 135, 137,I39, and 141 (FIG. I). In some applications, if preferred, the wire ropeand sheaves may be replaced by chains and sprockets, or any othersuitable mechanism may be used to accomplish the same purpose. Therollers 43, of course, coact with the top surface of the slab during thereturn travel of the yoke.

When the torch carriage approaches the initial position, an outwardlyprojecting member 143 on each side engages a buffer cylinder pistonwhich absorbs the momentum of the returning mechanism and whichgradually slows and stops the longitudinal motion of the mechanism.

Referring again to FIG. 3, it will be noted that, as the torch carriagemoves from left to right during cutting of the cast strand, the firstdogs 147, pivotally mounted to the underside of the carriage at theouter ends thereof, engage the upwardly projecting portion of the latch87, and pivot the latch clockwise. Other second dogs 149, likewisepivotally mounted to the underside of the carriage at the outer endsthereof, engage the roller 75 and pivot the tie member 73 and roller 75clockwise.

Because the pivot pin 71 cooperates with the oval hole 79, the center ofgravity of the tie member and the rollers is always below the centerlineaxis of the pin 71. Hence, when the dogs 149 pivot the tie members 71,they will continue to pivot due to the momentum generated by the seconddogs 149, and the bottom roller 77 will then be disposed at the top andthe former top roller 75 will be at the bottom. While the tie member androller have been pivoting, the torches 95, 97 will have moved past therollers 75, 77 without damaging either one of them.

When the roller 77 reaches the top position, it is prevented fromcontinuing to pivot by a stop 89a that engages the latch 87 which hasreturned to the engaging position due to the effect of its counterweight85.

In like manner the dogs 147 and 149 actuate the latches and rollers ofthe other roll stands 63 so that the torches 95, 97 do not damage theserollers when they move past them.

It is customary in continuous casting operations to separate thestarting bar from a head end portion that is integrally formed with thecast strand. Heretofore, it has been necessary to manually flame cut orcrop the starting bar head end portion from the strand. However, theapparatus of the invention is readily adapted to accomplish thisautomatically in the following manner.

At the front end of the torch carriage 37, there is a front croppingstop 151, which is pivotally attached to the carriage at 153. Thecropping stop is provided with a counterweight 155, as shown in FIGS. 2and 3, and also includes two side latches 157, 159, to maintain and holdthe stop 151 in the operative down position.

When it is desired to crop the head end of the cast strand, the frontcropping stop 151 is pivoted downwardly to the position 151a in FIG. 3.Then, the stop 151 is held in this down position by the side latches157, 159.

The head end of the cast strand 47, in moving from left to right in FIG.3 abuts the depressed cropping stop 151, and the torch carriage arms andyoke move in the same direction along the cast strand as describedpreviously. Immediately, the torches commence the cutting cycledescribed previously, and the torches crop the head end from the strand.

The cropped head end gravitates between the roll stands into a chute 161provided below the roll stands. The cropped head end gravitates into acar or other device and is thereafter removed to another location.

Immediately the head end has been cropped, the front cropping stop 151pivots clockwise to its original position and the counterweights 127,129 return the torch carriage, arms, and yoke to the initial position.

FIGS. 5-8 illustrate a modification of the apparatus of FIGS. 1-4.Because the modified apparatus is so similar to the apparatus describedpreviously herein it suffices to describe only the differences in theapparatus of FIGS. 5--8. The principal modifications reside in: a torchcarriage return mechanism; a support mechanism for the torches; and aslab support roller system.

Referring to FIG. 5, the torch carriage return mechanism comprises apair of hoisting drums 161, 163 which are driven by an electric motor165 acting through an appropriate speed reducer 167. The speed reducer167, the motor 165, and the hoisting drum 161, 163 are suitably mountedto support structure available nearby, but not shown. One end of suchwire rope cable 169 is fastened to the torch carriage frame 171 and thecables pass around sheaves 173, 175 that are similar to the sheaves 139,141 of FIG. 1. The other end of the wire rope cables 169 is loopedaround the hoisting drums 161 and 163.

The torch support mechanism includes pantographic mechanisms 177 and179, as shown in FIGS. 6 and 7. Each torch is similarly supported sothat a description of one torch support mechanism suffices for both.

The pantographic torch supporting mechanism 177 includes a pair ofelongate parallel arms 180, 180a that are pivotally connected to thetorches 95, 97 and that are pivotally connected to a short connectinglink 181. The connecting link 181 is pivotally mounted to one end of anelongate member 183 that is pivotally connected at the other end to afixed outwardly projecting portion 185 of the torch carriage frame 171.Each one of the elongate arms 180, 180a is pivotally mounted at aboutthe midlength point of each arm (FIG. 6) to other parallel pivotablelinks 187, 189 that are mounted to the torch carriage frame, about whereshown in FIGS. 6 and 7.

Each one of the slab supporting rollers, shown in FIG. 7, includes aslab roller 191 that is journaled at each end in pivotably supportingarms 193. The arms 193 are pivoted, as at 195, to upright fixed supportframes 197. Each one of the fixed support frames 197 also supportsrollers 69a on which the bars 550, 57a of the yoke 13a rest.

To each supporting arm 193 there is pivotally connected a toggleassembly comprised of two interconnected links 199, 201 which arepivotally connected together, as at 203, and to a piston rod 205 of acylinder piston assembly 207. The cylinder is pivotally mounted to thesupport frame 197, as at 209. Each supporting roller 191 isindependently driven by a small electric motor and gear reducer, or someother suitable source of rotary power, such as a motor and chain driveand gears, which are not shown.

The operation of the modified apparatus of FIGS. 57 is substantially thesame as the operation of the apparatus of FIGS. 1--4 described herein,except that the slab support rollers 191 are pivotally lowered, toprevent damage to them when the torches pass over the rollers, byactuating the cylinder piston 207. Of course, control of the actuatingmechanism for the cylinder piston 207 may be automatic, as by remotecontrol switches located on the beams 27, 29, or manual. Then, when thetorches approach the first roll stand, a first remote control switch isactuated whereby the cylinder piston 207 retracts the toggle linkage andthe support roller 191 pivotally lowers to the position shown by thedash-dot outline in FIG. 7. After the torches and slab have movedthrough a preselected distance, which distance is sufiicient to move thetorches past the roll stand, another switch may be actuated to motivatethe cylinder piston to pivotally raise the roller to its initialsupporting position.

Since the torches are guided by cam rods like those shown in FIG. 2,they move substantially the same way. The pantograph mechanism attachedto each torch provides support for each torch.

After the torches have cut a slab from the cast strand, and after theyoke has been disengaged from the end of the slab in the mannerdescribed previously, the hoisting motor 165, reducing gear 167, andhoisting drums 161, 163 may be automatically actuated to return thetorch carriage and yoke to its initial position.

Those skilled in the art will recognize many significant features andadvantages of the apparatus of the invention among which are;

That the apparatus is mechanically self-operating to effect rapid andefficient cutting of slabs from continuous cast strands;

That the apparatus is mechanically self-operating to trim and crop thehead end of a continuous cast strand;

That the apparatus is readily adjustable to cut slabs from strands ofdifferent widths and such adjustment may be made manually orautomatically.

We claim:

1. In a continuous casting machine wherein the cast strand advances in asubstantially horizontal plane, improved apparatus for cuttingindividual lengths from said strand comprising:

a. means for supporting said strand in said substantially horizontalplane;

b. a pair of first and second spaced apart frames established inposition straddling said strand supporting means and past which saidstrand advances;

c. first means engageable with the advancing front end of said strand;

d. a carriage movable along a path parallel to the path of said strandfrom an initial position to a second position;

e. second means connecting said first means to said carriage;

f. third means for maintaining said carriage movable along said path;

g. a flame cutting torch movably mounted to said carriage;

h. guide means mounted to said first and second frames and cooperativewith said torches whereby said torches move laterally of said strand andtoward each other as said carriage advances in the direction said strandmoves, and cuts said strand;

i. fourth means to disengage said first means from said strand aftersaid torches have cut said strand; and

j. fifth means to return said carriage and said first and second meansto said initial position.

2. The invention of claim 1 wherein:

a. said first means comprises i. a member extending transversely of saidstrand and having wheels at the side that are engageable with said thirdmeans, and ii. a surface that engages said strand.

3. The invention of claim 1 wherein:

a. said second means includes linking means.

4. The invention of claim 1 wherein:

a. said third means includes a pair of spaced apart rails ar ranged onopposite sides of said strand and disposed substantially parallel to thepath traversed by said strand.

. The invention of claim 1 wherein:

. said guide means includes i. at least two elongated members connectingtogether said first and second frames, and

ii. a pair of spaced apart rods adjustably mounted to each of saidelongate members, each said pair of rods coacting with one said torch toguide it.

6. The invention of claim 1 including:

a. adjustable means engageable with said strand for locating said guidemeans and said torches adjacent the edge of said strand.

7. The invention of claim 6 wherein:

a. said adjustable means includes i. two blocks slidable on the one ofsaid frames that is nearer said initial position.

8. The invention of claim 7 including:

a. a rotatable screw that coacts with said blocks for moving said blockslaterally of said strand.

9. The invention of claim 1 wherein:

a. said strand supporting means includes a plurality of roll standsdisposed between said frames and supporting said strand as it is beingcut by said torches, each said roll stand comprising at least oneroller;

b. means for disengaging the rollers of each roll stand successivelyfrom said strand as said torches pass over said roller while cuttingsaid strand; and

c. means for reengaging said roller of each roll stand successively withsaid strand after said torches have moved away from said roller.

10. The invention of claim 9 wherein:

a. said roller is joumaled to members that are mounted to each of saidroll stands on pivots.

11. The invention of claim 10 wherein:

a. said members support a pair of rollers journaled thereto at locationson opposite sides of said pivot; and including b. means to hold andmaintain one of said pair of rollers in supporting contact with saidstrand;

c. means to pivot said member and move said one roller to a positionwhere it is out of contact with said strand just before said carriageand the torches carried thereon pass over said roller while cutting saidstrand; and

d. means to pivot said member so that the other one of said rollers isbrought into supporting relation to said strand after said carriage andtorches have passed said roll stand.

12. The invention of claim 11 including:

a. latch means to hold and maintain said one or the other roller insupporting contact with said strand;

b. first means on said carriage to contact said latch and disengage it;

c. second means on said carriage engageable with the one roller incontact with said strand to pivot said member so that the other rolleris brought into contact with said strand and said member is latched.

13. In a continuous casting machine wherein the cast strand advances ina substantially horizontal plane, improved apparatus for cuttingindividual lengths from said strand comprising:

a. a pair of first and second spaced apart frames established inposition and past which said strand advances;

b. a member extending transversely of said strand and engageable withsaid strand;

c. a carriage movable along a path parallel to the path traversed bysaid strand from an initial position to a second position;

d. linking means connecting said transversely extending member to saidcarriage whereby when said transversely extending member engages saidstrand and moves along therewith said carriage also moves along withsaid strand;

e. a pair of spaced apart rails arranged on opposite sides of saidstrand and disposed substantially parallel to the path traversed by saidstrand, said carriage having means thereon that coact with said rails;

f. a first flame cutting torch movable mounted to said carriage;

g. a second flame cutting torch movably mounted to said carriage anddisposed in a plane normal to said strand and containing said firstflame cutting torch;

h. guide members connecting together said first and second j. means todisengage said transversely extending member from said strand after saidtorches have out said strand in two;

means to return said carriage from said second position to said firstposition;

. a plurality of roll stands disposed between said frames and supportingsaid strand as it is being cut by said torches, each said roll standcomprising at least one roller;

m. a member mounted to each roll stand that is pivotable about ahorizontal axis and which contains journals for supporting each roll;

It. means to hold and maintain said roller in supporting contact withsaid strand;

0. means to pivot said member and move said roll to a position where itis out of contact with said strand just before said carriage and thetorches carried thereon pass over said roller while cutting said strand;and p. means to pivot said member so that said roller lS brought intosupporting contact with said strand after said carriage and torches havepassed said roll stand.

14. The invention of claim 13 wherein:

a. said means to hold and maintain said roll in supporting contact withsaid strand includes a toggle mechanism and a fluid actuatedpiston-cylinder assembly thereto connectedl 15. The invention of claim13 including:

a. a second roller journally mounted to said member on the opposite sideof said pivot;

b. latch means to hold and maintain said one or the other of saidrollers in supporting contact with said strand;

c. first means on said carriage to contact said latch and disengage itjust before said torches reach the position of said first roll stand;and

d. second means on said carriage engageable with the one roller incontact with said strand to pivot said member so that the other rolleris brought into contact with said strand and said member is latched inposition after said torches have passed the location of said first rollstand.

